/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 22 What is the Doppler effect? Why ... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 5: Problem 22

What is the Doppler effect? Why is it important to astronomers?

Short Answer

Expert verified
The Doppler Effect is the change in frequency or wavelength of a wave for an observer moving relative to its source. It is important to astronomers as it enables the measurement of velocities of distant celestial bodies, the discovery of exoplanets, and supports our current understanding that the universe is expanding based on the redshift seen in light from distant galaxies.

Step by step solution

01

Understanding The Doppler Effect

The Doppler Effect, named after the Austrian physicist Christian Doppler, refers to the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. For example, if a source of sound is moving towards an observer, they will perceive the sound as being higher in pitch (higher frequency) than it actually is. If the source of sound is moving away from the observer, they will perceive it as being lower in pitch (lower frequency). The same effect occurs with light waves.
02

The Doppler Effect in Astronomy

This is important in the field of astronomy as it allows for the measurement of speed and direction of distant galaxies or stars relative to the observer on earth. When a star or galaxy is moving away, the light waves emitted undergo a redshift (increase in wavelength or decrease in frequency) as perceived from the observer on earth. When the star or galaxy is moving closer, the opposite happens, a blueshift (decrease in wavelength or increase in frequency) is observed. This provides crucial data about the movement of celestial bodies in the universe.
03

Importance of the Doppler Effect to Astronomers

By measuring the degree of redshift or blueshift, astronomers can determine the speed at which a star or galaxy is moving towards or away from us. More importantly, this effect revealed that the universe is expanding, which is fundamental to our current understanding of the universe. This realization originated from observing a general redshift in light from distant galaxies, indicating they are moving away from us, leading to the formulation of the Big Bang Theory.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

You are given a traffic ticket for going through a red light (wavelength \(700 \mathrm{~nm}\) ). You tell the police officer that because you were approaching the light, the Doppler effect caused a blueshift that made the light appear green (wavelength \(500 \mathrm{~nm}\) ). How fast would you have had to be going for this to be true? Would the speeding ticket be justified? Explain.

To emit the same amount of light energy per second, which must emit more photons per second: a source of red light, or a source of blue light? Explain.

For each of the following wavelengths, state whether it is in the radio, microwave, infrared, visible, ultraviolet, X-ray, or gamma-ray portion of the electromagnetic spectrum. Explain your reasoning. (a) \(2.6 \mu \mathrm{m}\), (b) \(34 \mathrm{~m}\), (c) \(0.54 \mathrm{~nm}\), (d) \(0.0032\) \(\mathrm{nm}\), (e) \(0.620 \mu \mathrm{m}\), (f) \(310 \mathrm{~nm}\), (g) \(0.012 \mathrm{~m}\).

(a) Calculate the wavelength of \(P_{\delta}\) (P-delta), the fourth wavelength in the Paschen series. (b) Draw a schematic diagram of the hydrogen atom and indicate the electron transition that gives rise to this spectral line. (c) In what part of the electromagnetic spectrum does this wavelength lie?

Approximately how many times around the Earth could a beam of light travel in one second?
See all solutions

Recommended explanations on Physics Textbooks

Work Energy and Power

Read Explanation

Medical Physics

Read Explanation

Energy Physics

Read Explanation

Electricity and Magnetism

Read Explanation

Turning Points in Physics

Read Explanation

Famous Physicists

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.